Catathrenia: A rare disorder presenting as daytime sleepiness and headache
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/neuroindia.NI_874_16
Source of Support: None, Conflict of Interest: None
Catathrenia or sleep related groaning is a rare disorder that is characterized by a moaning sound which is produced during prolonged expiration, primarily during rapid eye movement (REM) sleep but it can also be seen during non-rapid eye movement (NREM) sleep., Its clinical significance is not known because it is not associated with significant hypoxemia or sleep apnea. However, these patients have a high arousal index and a consequent daytime fatigue or somnolence., Due to this reason, these patients may seek help of sleep-physicians or neuropsychiatrists. Other common reasons for seeking medical help include interference with the sleep of bed partner by the moaning sound of the patient; and, if groaning has sexual connotations, it become a social problem.,
We are reporting a case of a young male patient who sought help from a psychiatrist for morning headache and excessive fatigue during the day, along with production of abnormal sounds at night. On polysomnography, he was diagnosed as having catathrenia with sleep related bruxism.
A 26-year old young male patient had a history of moaning during sleep, bi-temporal headache after waking up and a non-refreshing sleep pattern. He was reported to be having multiple episodes of moaning during most of the nights of a given week. The sound was loud enough to disrupt the sleep of the person sharing the room with him. It was interfering with his professional activities since his job required him to stay away from home and to share the room with his colleagues. It made him to seek medical opinion.
He had this problem since adolescence, as was reported by family members; however, he was oblivious of this issue. His moaning during sleep was monotonous with varying amplitude and duration and with multiple occurrences each night. He was reported to be having a similar problem during naps as well.
In addition, he complained of bitemporal headache in the morning that used to improve by afternoon. Headache was dull and aching and was not associated with any other symptom. The family members could not comment on associated teeth grinding during sleep; however, pain in the jaws was reported upon awakening.
Non-refreshing sleep, almost on a daily basis, was reported since adolescence and the patient often felt tired or sleepy during the day. His Epworth Sleepiness Scale score was 12. There was no history to suggest obstructive sleep apnea, restless leg syndrome, narcolepsy, circadian rhythm sleep disorder or parasomnia. His medical history was non-remarkable. There was no family history of similar symptoms, sleep disorders or medical disorders.
On examination, he had an ectomorphic and an athletic built. The Mallampatti score was 2; tonsils were not hypertrophied; hard palate, soft palate and uvula were normal. The tongue size was also normal and the nasal airway was bilaterally patent. His weight was 95 kg and height was 180 cm; the body mass index was 29.3 kg/m 2. His neck circumference was 14 inches. Bilateral temporal and masseter muscles were normal, and the temporo-mandibular joints did not have a click or tenderness. Teeth and chest examination were also normal.
Considering the history and examination, a clinical diagnosis of catathrenia with sleep-related bruxism was made and polysomnography was advised.
He was subjected to a video-synchronized level-1 polysomnography for two nights using Alice-5 diagnostic system (Philips-Respironics) after acclimatization to the sleep laboratory. Diagnostic montage was placed and scoring was done by a trained scorer according to the American Academy of Sleep Medicine manual.
The output of the polysomnography reports for both the nights is shown in [Table 1]. During the first study, catathrenia was witnessed for the first time during the first episode of rapid-eye-movement sleep (REM). During the first night, 43 episodes of catathrenia, lasting between 2-18 seconds, were observed during REM sleep while only 7 events were observed during N2 sleep (duration range: 3-7 seconds). On the subsequent night, the first event of catathrenia appeared during the first episode of N2 sleep. A total of 16 events occurred during N2 sleep (duration: 2-10 seconds) and 31 events during REM sleep, each lasting between 4-17 seconds. Events were crowded towards the second half of the sleep and were seen in clusters in both nights. Most of the events were preceded by a leg movement (78%), had associated arousal (92% of the total) and some were associated with bruxism (8% of the total). Rhythmic masticatory muscle movement activity (RMMA) was observed both during N2 as well as during REM sleep. It was seen with and without catathrenia [Figure 1].
Previous literature reports that polysomnographically, catathrenia is manifested as prolonged expiration, bradypnea and prolonged sound signals during N2 and REM sleep with predominance towards the second half of the night., The sound has been reported to follow the crescendo-decrescendo pattern and is initiated with an arousal.
This disorder has been reported to start during the childhood or adolescence and most of these patients have a normal body mass index (BMI)., The groaning sound is produced by the subtotal closure of glottis and the pharyngeal muscles do not play any role in producing it.
Catathrenia is differentiated from central sleep apnea by the presence of vocalization; from sleep related seizures by electroencephalography; from sleep related laryngospasm by the differing clinical symptoms; and, from expiratory snoring by the peculiar quality and duration of sound. We found that in addition to catathrenia, the patient had a few episodes of central sleep apnea, which, however, were clinically insignificant. Association with sleep related breathing disorders has been reported in one case series but not in the other.,
This case was also different because it reported daytime sleepiness, a finding that has been reported only in one case series so far. Other case series reported a high respiratory disturbance index but did not find excessive daytime sleepiness in their subjects. Daytime sleepiness has been found to have an association with the arousal index. It has been proposed that nocturnal sleep fragmentation seen in these patients could be responsible for daytime sleepiness.
Whether or not catathrenia represents a sleep related breathing disorder or parasomnia, is still a matter of debate, perhaps owing to the small number of reported cases. Iriate et al., proposed that this disorder could represent both the entities, depending upon the characteristics of the polysomnographic findings. Events with longer duration (>2 sec), predominantly seen during REM sleep and associated with central sleep apnea favor the possibility of it being a respiratory disorder, while the short duration events (1-3 sec), seen during REM/NREM sleep and showing obstructive hypopnea may represent parasomnia. In this patient, we observed events occurring predominantly during REM sleep on both the nights. The episodes were of long duration in the absence of a clinically significant sleep related breathing problem. Absence of obstructive hypopnea, presence of central sleep apnea and predominance during the REM sleep favor the entity to be representing a respiratory pathology in the present patient. Perhaps, our understanding regarding the distinction between the two (respiratory disorder vs parasomnia) is nebulous owing to the limited literature available. We observed that a leg movement and/or an arousal preceded most of the events. This brief arousal may produce instability in the state of consciousness across various brain areas that can result in parasomnias. However, some of the events were not preceded by arousal and/or leg movements that supports the fact that it could be due to a respiratory disorder as well [Figure 1].
The patient also had the clinical symptoms of sleep related bruxism. Bruxism and parasomnias have been observed in 3 of the seven cases reported by Guilliminault et al., and 4 of the eight cases reported by Prihodova et al. The International Classification of Sleep Disorder-3rd edition describes that sleep related bruxism appears after a transient arousal or during a respiratory disorder, a finding that was seen in the present case as well. [Figure 1] shows that rhythmic masticatory movement activity (RMMA) was associated with prolonged expiration and bradypnea. This is not seen in patients of sleep related bruxism who do not have catathrenia. Considering this fact and the high degree of concordance between RMMA and catathrenia, it may be possible that either of the conditions arise out of a disturbance in the maintenance of sleep state or they may have a common neurobiological mechanism.
In conclusion, catathrenia is a rare disorder, which can produce subjective symptoms in addition to social disturbances. Many patients may have poor quality sleep along with daytime symptoms. These patients should always be screened for parasomnia or sleep related movement disorders.
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